lazy load

djconfig/__init__.py

@@ -2,80 +2,9 @@
 
 from __future__ import unicode_literals
 
-from django.core.cache import get_cache
-from django.db import connection
-from django.conf import settings as django_settings
-
-from djconfig.forms import ConfigForm
-from djconfig.config import config, prefixer
-from djconfig.models import Config as ConfigModel
-from djconfig.settings import BACKEND, PREFIX
+from djconfig.config import config
+from djconfig.registry import register, load
+from djconfig.settings import BACKEND
 
 __version__ = "0.1.8"
-__all__ = ['config', 'register']
-
-_registered_forms = set()
-
-
-def register(form_class):
-    """
-    Register config forms
-
-    :param form_class: The form to be registered.
-    :type form_class: ConfigForm.
-    """
-    global _registered_forms
-
-    assert issubclass(form_class, ConfigForm), \
-        "The form does not inherit from ConfigForm"
-
-    _registered_forms.add(form_class)
-    _check_backend()
-    _load()
-
-
-def load():
-    """
-    Loads every registered form into the cache.
-    If a field name is found in the db, it will load it from there.
-    Otherwise, the initial value from the field form is used.
-    """
-    global _registered_forms
-
-    cache_values = {}
-    data = dict(ConfigModel.objects.all().values_list('key', 'value'))
-
-    for form_class in _registered_forms:
-        form = form_class(data=data)
-        form.is_valid()
-
-        initial = {prefixer(field_name): field.initial
-                   for field_name, field in form.fields.items()}
-        cache_values.update(initial)
-
-        cleaned_data = {prefixer(field_name): value
-                        for field_name, value in form.cleaned_data.items()
-                        if field_name in data}
-        cache_values.update(cleaned_data)
-
-    cache_values[prefixer('_updated_at')] = data.get('_updated_at')
-    cache = get_cache(BACKEND)
-    cache.set_many(cache_values)
-
-
-def _load():
-    """
-    Avoids loading if the Config table does not exists.
-    ie: when running syncdb for the first time.
-    """
-    if not ConfigModel._meta.db_table in connection.introspection.table_names():
-        return
-
-    load()
-
-
-def _check_backend():
-    if django_settings.CACHES[BACKEND]['BACKEND'].endswith(".LocMemCache") and \
-            "djconfig.middleware.DjConfigLocMemMiddleware" not in django_settings.MIDDLEWARE_CLASSES:
-        raise ValueError("LocMemCache requires DjConfigLocMemMiddleware "
-                         "but it was not found in MIDDLEWARE_CLASSES")
+__all__ = ['config', 'register', 'load', 'BACKEND']

djconfig/config.py

@@ -4,23 +4,31 @@
 
 from django.core.cache import get_cache
 
-from djconfig.settings import BACKEND, PREFIX
-
-
-def prefixer(key):
-    return "%s:%s" % (PREFIX, key)
+from djconfig.settings import BACKEND
+from djconfig.utils import prefixer
+from djconfig import registry
 
 
 class Config(object):
 
     def __init__(self):
         self._cache = get_cache(BACKEND)
+        self._is_loaded = False
 
     def __getattr__(self, key):
+        self._lazy_load()
         return self._cache.get(prefixer(key))
 
     def _set(self, key, value):
+        self._lazy_load()
         self._cache.set(prefixer(key), value)
 
+    def _lazy_load(self):
+        if self._is_loaded:
+            return
+
+        self._is_loaded = True
+        registry.load()
+
 
 config = Config()

djconfig/registry.py

@@ -0,0 +1,65 @@
+#-*- coding: utf-8 -*-
+
+from __future__ import unicode_literals
+
+from django.core.cache import get_cache
+from django.conf import settings as django_settings
+
+from djconfig.forms import ConfigForm
+from djconfig.models import Config as ConfigModel
+from djconfig.settings import BACKEND
+from djconfig.utils import prefixer
+
+_registered_forms = set()
+
+
+def register(form_class):
+    """
+    Register config forms
+
+    :param form_class: The form to be registered.
+    :type form_class: ConfigForm.
+    """
+    global _registered_forms
+
+    assert issubclass(form_class, ConfigForm), \
+        "The form does not inherit from ConfigForm"
+
+    _registered_forms.add(form_class)
+    _check_backend()
+
+
+def load():
+    """
+    Loads every registered form into the cache.
+    If a field name is found in the db, it will load it from there.
+    Otherwise, the initial value from the field form is used.
+    """
+    global _registered_forms
+
+    cache_values = {}
+    data = dict(ConfigModel.objects.all().values_list('key', 'value'))
+
+    for form_class in _registered_forms:
+        form = form_class(data=data)
+        form.is_valid()
+
+        initial = {prefixer(field_name): field.initial
+                   for field_name, field in form.fields.items()}
+        cache_values.update(initial)
+
+        cleaned_data = {prefixer(field_name): value
+                        for field_name, value in form.cleaned_data.items()
+                        if field_name in data}
+        cache_values.update(cleaned_data)
+
+    cache_values[prefixer('_updated_at')] = data.get('_updated_at')
+    cache = get_cache(BACKEND)
+    cache.set_many(cache_values)
+
+
+def _check_backend():
+    if django_settings.CACHES[BACKEND]['BACKEND'].endswith(".LocMemCache") and \
+            "djconfig.middleware.DjConfigLocMemMiddleware" not in django_settings.MIDDLEWARE_CLASSES:
+        raise ValueError("LocMemCache requires DjConfigLocMemMiddleware "
+                         "but it was not found in MIDDLEWARE_CLASSES")

djconfig/tests.py

@@ -11,7 +11,8 @@
 from django.conf import settings
 
 import djconfig
-from djconfig import prefixer
+from djconfig.registry import _registered_forms, load
+from djconfig.utils import prefixer
 from djconfig.forms import ConfigForm
 from djconfig.models import Config as ConfigModel
 from djconfig.config import Config as ConfigCache
@@ -35,7 +36,7 @@ class DjConfigTest(TestCase):
 
     def setUp(self):
         _cache.clear()
-        djconfig._registered_forms.clear()
+        _registered_forms.clear()
 
         self.cache = get_cache(djconfig.BACKEND)
 
@@ -44,7 +45,7 @@ def test_register(self):
         register forms
         """
         djconfig.register(FooForm)
-        self.assertSetEqual(djconfig._registered_forms, {FooForm, })
+        self.assertSetEqual(_registered_forms, {FooForm, })
 
     def test_register_invalid_form(self):
         """
@@ -60,6 +61,7 @@ def test_load(self):
         Load initial configuration into the cache
         """
         djconfig.register(FooForm)
+        load()
         keys = ['boolean', 'boolean_false', 'char', 'email', 'float_number', 'integer', 'url']
         values = self.cache.get_many([prefixer(k) for k in keys])
         self.assertDictEqual(values, {prefixer('boolean'): True,
@@ -84,6 +86,7 @@ def test_load_from_database(self):
         ConfigModel.objects.bulk_create(data)
 
         djconfig.register(FooForm)
+        load()
 
         keys = ['boolean', 'boolean_false', 'char', 'email', 'float_number', 'integer', 'url']
         values = self.cache.get_many([prefixer(k) for k in keys])
@@ -106,6 +109,7 @@ def test_load_unicode(self):
         """
         ConfigModel.objects.create(key='char', value=u"áéíóú")
         djconfig.register(FooForm)
+        load()
         self.assertEqual(self.cache.get(prefixer('char')), u"áéíóú")
 
     def test_load_from_database_invalid(self):
@@ -114,6 +118,7 @@ def test_load_from_database_invalid(self):
         """
         ConfigModel.objects.create(key='integer', value="string")
         djconfig.register(FooForm)
+        load()
         self.assertEqual(self.cache.get(prefixer('integer')), 123)
 
     def test_load_updated_at(self):
@@ -139,7 +144,7 @@ class DjConfigFormsTest(TestCase):
 
     def setUp(self):
         _cache.clear()
-        djconfig._registered_forms.clear()
+        _registered_forms.clear()
 
     def test_config_form(self):
         """
@@ -210,7 +215,7 @@ class DjConfigConfTest(TestCase):
 
     def setUp(self):
         _cache.clear()
-        djconfig._registered_forms.clear()
+        _registered_forms.clear()
 
     def test_config(self):
         """
@@ -236,7 +241,7 @@ class DjConfigMiddlewareTest(TestCase):
 
     def setUp(self):
         _cache.clear()
-        djconfig._registered_forms.clear()
+        _registered_forms.clear()
 
     def test_config_middleware_process_request(self):
         """
@@ -329,7 +334,7 @@ class DjConfigUtilsTest(TestCase):
 
     def setUp(self):
         _cache.clear()
-        djconfig._registered_forms.clear()
+        _registered_forms.clear()
 
     def test_override_djconfig(self):
         """

djconfig/utils.py

@@ -3,13 +3,19 @@
 from __future__ import unicode_literals
 from functools import wraps
 
-from . import config
+from djconfig.settings import PREFIX
+
+
+def prefixer(key):
+    return "%s:%s" % (PREFIX, key)
 
 
 def override_djconfig(**new_cache_values):
     """
     This is similar to Django's @override_settings, use it in testing.
     """
+    from . import config
+
     def decorator(func):
         @wraps(func)
         def func_wrapper(*args, **kw):

example/settings.py

@@ -90,4 +90,4 @@
     'default': {
         'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
     }
-}
+}